How do I solve periodic mouse lag on Linux Mint (MATE)?

I found the following solution on Ask Ubuntu:

sudo -i
echo N> /sys/module/drm_kms_helper/parameters/poll
echo "options drm_kms_helper poll=N">/etc/modprobe.d/local.conf

It definitively solved the problem for me, and after more than a week of testing I can confirm it stopped the mouse lag for me.

Note that on newer kernels the drm_kms_helper module may not be loaded by default. One extra step gets this working:

sudo su -
modprobe drm_kms_helper
echo N> /sys/module/drm_kms_helper/parameters/poll
echo "drm_kms_helper" >> /etc/modprobe.d/local.conf
echo "options drm_kms_helper poll=N" >> /etc/modprobe.d/local.conf

Hope that helps someone!

Fixing Mouse Lag on Cinnamon

I have experienced heavy mouse lag on cinnamon suddenly. In case someone else finds this page when searching, like me, for a possible cause, it is perhaps: Desktop magnification. Make sure it is turned off with Alt+Super+8, even when the screen is not magnified.

It took me quite some time to track it down, mainly found the problem after starting to bisect my entire home directory (move half of the directories to a temporary directory and log in again etc.) until I could locate ~/.config/dconf/user and then finally the zoom level factor that was set to 1.0:

[org/cinnamon/desktop/a11y/magnifier]
mag-factor=1.0
screen-magnifier-enabled=true

You can check if this is the case on your Cinnamon with

dconf dump / |grep mag